Wow, neat!
I wonder if they encrypted the roms to make it a little tricky to find?
I remember once extracting a nes rom, which was only released on physical cartridge and on a Windows emulator with the game embedded so that it looked like a native windows game. After freezing the process and dumping the memory about 100 times, I finally found the nes header ("NES\x1a") using a binary search on the dump. The appl. removed the nes header from the rom right after decrypting it and loading it into the emulator.
Anyhow, good luck!
best regards,
- dink